In fuel injectors for internal combustion engines, it is important to minimize contaminants introduced to the fuel injector. Contaminants may interfere with the fuel injector valve operation if they adhere to the valve seat and prevent the valve from completely seating. One source of contaminants may be the entering fuel which may be filtered with an external filter upstream of the fuel injector inlet. Contaminants may also originate within the fuel injector during the manufacturing process and such contamination is not affected by an external upstream filter. One means known to reduce these manufacturing contaminants is with an internal filter located upstream of the valve, supported by an adjacent, downstream valve guide. This filtration system adds a separate part to the fuel injector assembly.